The present invention relates generally to Stirling-cycle cryogenic coolers, and more particularly, to a Stirling-cycle cryogenic cooler having an adaptive feedforward vibration control system and procedure and a spacecraft employing such a Stirling-cycle cryogenic cooler.
The assignee of the present invention designs and builds spacecraft employing infrared and other imaging sensors. These imaging sensors in general are cooled to very low temperatures (65.degree. Kelvin) by cryogenic coolers. However, the coolers employ moving compressor and expander pistons that produce vibration that limits the performance of the imaging sensors. Consequently, vibration control systems and procedures have been developed to minimize the effects of vibration of the cryogenic cooler.
One narrow-band vibration control procedure has previously been developed by the assignee of the present invention that is adapted to reduce the vibration associated with Stirling-cycle cryogenic coolers employed on its spacecraft. However, it has been determined that the computational throughput required to implement this procedure is undesirably high. This computational inefficiency results in greater weight of the spacecraft, which is undesirable.
Therefore, it is an objective of the present invention to provide for an improved vibration control procedure for use with a Stirling-cycle cryogenic cooler. It is a further objective of the present invention to provide for a vibration control procedure for use with a Stirling-cycle cryogenic cooler that is computationally efficient in order to reduce the weight of the processors and components required to implement it.